moved less file that caused travis build error

src/css/less/grafana.less

@@ -1,5 +1,5 @@
 @import "submenu.less";
-@import "..\..\vendor\tagsinput\bootstrap-tagsinput.less";
+@import "bootstrap-tagsinput.less";
 
 .navbar-static-top {
   border-bottom: 1px solid black;